The present invention is directed to a lockup assembly for a planting unit having a lockup link and a control link, wherein the control link has a normal position and a lockup position for engaging the lockup link.
Planting units are typically coupled to a toolbar by parallelogram linkages so that the planting units can move vertically a limited amount relative to the toolbar. Sometimes a farmer wishes to deactivate or lockup one or more planting units. For example, a farmer with planting units on fifteen-inch rows for soybeans may want to switch to thirty-inch rows for corn. The farmer would lockup every other planting unit to plant the corn.
Lockup units are well known in the art. One example is disclosed in U.S. Pat. No. 4,738,317.
It is an object of the present invention to provide a planting unit lockup assembly that is compact and easy to operator.
The planting unit lockup assembly extends between upper and lower links of a parallelogram linkage. The lockup assembly comprises a lockup link and a control link. The lockup link is pivotally coupled to the upper link and extends downwardly to the lower link. The lockup link is also provided with a slot having a hook. A slide bushing member is mounted to the lower link and engages the slot. The control link is pivotally coupled to the lockup link by a loose pivot coupling. The control link is biased towards the lower link by a spring extending from the control link to the lower link. The control link is provided with a trapping element that engages the lockup link. The trapping element of the control link engages the lockup link in one of two positions, a normal position and a lockup position. In the normal position, the trapping element engages an aperture located in the lockup link. In its lockup position, the trapping element engages the side edge of the lockup link. In its normal position, the control link through the trapping element biases the hook away from the slide bushing member. In its lockup position the control link through the trapping element biases the hook towards the slide bushing member. The control link is provided with a handle for switching the control link between the two positions.
The control link is located between the left and right parallelogram linkages. Only the handle extends outwardly from the parallelogram linkages. This reduces the width requirements for the lockup assembly.